86 



THE TEACHING BOTANIST 



the following. There should be one or two large tables 

 for holding the supply of material for the class and 

 for demonstration, etc. These may be built three feet 

 high, with lockers for microscopes, or other storage, 

 beneath. A teacher's platform with a blackboard is 

 essential, and over it, as well as elsewhere in the room, 

 should be racks for displaying diagrams. The best racks 

 I know of are boards an inch thick, four inches wide, 

 B A an d ten feet long, 



rounded on one 

 edge to hold Den- 

 nison's No. 12 Card 

 P Holders (which are 

 far the best dia- 

 gram holders I 

 have ever seen) ; 

 these boards 



D 



run 



FIG. 5. A successful rack for displaying j n a lio-flt 

 diagrams. A, B, pulleys ; C, cleat for 



fastening cords ; D, cross-section of the frame, like a WH1- 



guiding-case, enlarged. i r , 



i dow frame, and are 



raised and lowered by cords attached as shown in Fig. 

 5, which also shows a cross-section of the guiding- 

 case. The latter, however, is not indispensable. Two 

 boards may be used in the same case, passing one 

 another and giving two tiers of diagrams if the ceil- 

 ing is high enough either above the blackboard, or 

 elsewhere. A gas table for heating, glass-bending, etc., 

 is necessary, as is a large sink (preferably porcelain- 



